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The closest analogs within the Milky Way galaxy of the stars producing long gamma-ray bursts are likely the Wolf–Rayet stars, extremely hot and massive stars, which have shed most or all of their hydrogen envelope. Eta Carinae, Apep, and WR 104 have been cited as possible future gamma-ray burst progenitors. [121]
A gamma ray, also known as gamma radiation (symbol. γ. ), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (3 × 1019 Hz) and wavelengths less than 10 ...
A practical fallout shield is ten halving-thicknesses of a given material, such as 90 cm (36 inches) of packed earth, which reduces gamma ray exposure by approximately 1024 times (2 10). [ 44 ] [ 45 ] A shelter built with these materials for the purposes of fallout protection is known as a fallout shelter .
The history of gamma-ray [1] began with the serendipitous detection of a gamma-ray burst (GRB) on July 2, 1967, by the U.S. Vela satellites. After these satellites detected fifteen other GRBs, Ray Klebesadel of the Los Alamos National Laboratory published the first paper on the subject, Observations of Gamma-Ray Bursts of Cosmic Origin. [2]
Gamma radiation detected in an isopropanol cloud chamber. Gamma (γ) radiation consists of photons with a wavelength less than 3 × 10 −11 m (greater than 10 19 Hz and 41.4 keV). [4] Gamma radiation emission is a nuclear process that occurs to rid an unstable nucleus of excess energy after most nuclear reactions. Both alpha and beta particles ...
The typical gamma rays given off by the weapon have an energy of about 2 MeV (mega electron-volts). The gamma rays transfer about half of their energy to the ejected free electrons, giving an energy of about 1 MeV. [24] In a vacuum and absent a magnetic field, the electrons would travel with a current density of tens of amperes per square metre ...
X-rays normally have a lower energy than gamma rays, and an older convention was to define the boundary as a wavelength of 10 −11 m (or a photon energy of 100 keV). [14] That threshold was driven by historic limitations of older X-ray tubes and low awareness of isomeric transitions. Modern technologies and discoveries have shown an overlap ...
z = 0.125. Swift. Either a long-duration burst in which the presence of a bright supernova is ruled out, or a short-duration burst with extremely long-lasting gamma-ray emission. GRB 080319B. z = 0.937. Swift. The most (optically) luminous event of any nature observed in the universe to date. By far the brightest optical afterglow of any gamma ...